• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.691-698
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• 2000

Volatile flavor components in the mash of takjus prepared by using Rhizopus japonicus nuruk were identified by using GC and GC-MS. Twenty-four esters, 19 alcohols, 9 acids, 10 aldehydes and 4 others were found in the mash of takju. Thirty nine components including 14 esters and 12 alcohols were detected in the beginning of fermentation. Seventeen components were more detected after second day of fermentation and 66 components were detected after 12 days of fermentation. Thirty eight flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol and 3-methyl-1-butanol, 14 esters such as ethylacetate, ethylcaprylate and isoamylacetate, 6 aldehydes and 5 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of 76.2149-92.1155% as a major component by using relative peak area. 3-Methyl-1-butanol, 2-methyl-1-propanol, ethyl caprylate, 2,3-butanediol and benzeneethanol were some of the major volatile components through the fermentation. Peak area of ethylacetate, diethyl succinate, octanoic acid, acetic acid and isobutylaldehyde among the same group were higher than other component depending upon fermentation time.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.478-483
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• 1995

To investigate the constituents of antimutagenic factor from brown rice, methanol extracts were fractionated into ether, ethylacetate, buthanol and aqueous fractions. The ether fractions showed distinct antimutagenic effect and active spot were selected by silica gel chromatography. The specific activity of active spot decreased with isolation of the active components from the methanol extract. Qualitative analyses of the active spot by using various spraying reagents revealed that ninhydrin and orcinol did not develop colored reactions. But, ferric chloride, 2,7-dichlorofluorescein, antimony pentachloride, phosphomolybdic acid, bromothymol blue and rhodamine 6G led to colored reactions. These results suggested that the consitituents of active material were neither polar nor nitrogen-containing compounds and that they may contain phenolic compounds and fatty acid derivatives. Main compounds of the active spot were analyzed to be o-hydroxy benzyl alcohol(saligenin), octanoic acid(caprylic acid), 9,12-cis-octadecadienoic acid(linoleic acid), 11-cis-octadecenoic acid(oleic acid), hexadecanoic acid(palmitic acid), 1H-indole-2-carboxylic acid and 1,2-benzenedicarboxylic acid(phthalate) in GC/Mass spectrum, and antimutagenicity of these active compounds using standard regeant was reconfirmed in S. typhimurium reversion assay.

• Food Science and Preservation
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• v.20 no.2
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• pp.207-214
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• 2013

This study was conducted to investigate changes in the main volatile flavor components of oriental melon during the process of alcohol fermentation via SPME (solid phase micro extraction). The flavor components of oriental melon were shown to have mainly included melon and green flavors. The green flavor was identified to be nonanal, 1-butanol, 1-octen-2-ol and benzene, and its relative concentration was shown to be 16.66%. The nonanal concentration was shown to have been reduced among the green-flavor components, but no significant change in remaining components was observed. Mainly, sweet flavor tended to increase, and the relative concentration of benzene was particularly shown to have increase by 25.58%, accounting for the highest relative concentration. The amount of green-flavor components, except for 1-butanol, was shown to have significantly decrease after alcohol fermentation. Then, no component of green-flavor, which causes an offensive smell, was found during fermentation and aging. Meanwhile, the volatile flavor components, which are consist of acids, were shown to have been produced during alcohol fermentation. In particular, octanoic acid, which causes off-flavor, was shown to be 60.99%, a very high relative concentration during the aging stage. In addition, acetic acid with a pungent sour flavor tended to be produced. A further study on the improvement of flavor in the production of oriental melon wine is required.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.430-436
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• 2016

Solid phase microextraction and gas chromatography-mass spectrometry (SPME/GC-MS), electronic nose, and electronic tongue were used to characterize the sensory profiles of cider vinegars from Korea (K1-2), China (C1-2), Japan (J1-2), and US (U1-2). SPME-GC/MS detected acetic acid as the common volatile compound in all vinegars, in addition to isovaleric acid, octanoic acid, and phenethyl acetate. Acids and acetic esters were the major components of Korean and US vinegar samples, respectively. Chinese vinegars had high ethyl acetate content, while Japanese samples were characterized by a low content of acetic acid. Principal component analysis (PCA) pattern provided a clear categorical discrimination of Chinese vinegars by E-nose and E-tongue analyses. The instrumental sensory scores and the taste attributes for flavor ($r^2=0.9431$), sourness ($r^2=0.9515$), and sweetness ($r^2=0.8325$) were highly correlated. Therefore, SPME/GC-MS, E-nose, and E-tongue analyses may be useful tools to discriminate the sensory profiles of cider vinegars of different origins.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.7-15
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• 2022

Volatile and non-volatile metabolite profiles of sugar-immersed raspberry liquid during different storage periods were analyzed and comparative analysis with their general characteristics, antioxidant activity, and sensory quality was evaluated to better understand the effect of the storage period on the quality of ugar-immersed raspberry liquid. During storage, a browning reaction occurred, resulting in a change in color and the production of volatile compounds. At the beginning of storage, sucrose was completely decomposed into fructose and glucose, and the sweetness was rapidly reduced, but the increase in succinic acid increased the sour taste. Most volatile compounds increased with an increase of the storage period, and especially, the contents of citronellol, octanoic acid, and hexanoic acid, which are known as antioxidants, showed the highest content in 10 day-sample, showing the highest antioxidant activity at this time. Although a further study on bacterial profiles and browning reaction during the storage will be needed, the results of this study showed that the quality of sugar-soaked raspberry extract was significantly affected by the storage period and can be used as basic data for commercialization of ugar-immersed raspberry liquid.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.391-396
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• 1997

Two series of carbon sources, linear primary $C_1$~$C_9$ alcohols and linear $C_2$~$C_{10}$ monocarboxylic acids were tested for PHA synthesis in Paracoccus denitrificans. The results showed that the growth-associated synthesis of PHA could be referred only to the carbon sources with odd number of carbon except methanol. For all carbon sources with even number of carbon, nitrogen limitation was required to induce PHA synthesis in P. denitrificans. Poly(3-hydroxyvalerate)[P(3HV)] homopolymer was synthesized from $C_5$, $C_7$, and $C_9$ while growing in the presence of nitrogen, but the nitrogen depletion in the later growth period incorporated 3-hydroxybutyrate(3HB) unit into the polymer chain. The optimum C/N ratio for P(3HV) homopolymer production was found to be 10 when the strain was grown on 10 ml/l of valeric acid for 96 h. P. denitrificans synthesized P(3HB-co-3HV) copolymers from n-hexanoic and n-octanoic acid. The microstructural characterics of the P(3HB-co-3HV) copolymer from n-propanol was investigated using $^13C$-nuclear magnetic resonance spectroscopy, showing a structural heterogeneity.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.179-186
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• 2009

The chemical composition of essential oil from the perennial herbaceous plants (Houttuynia cordata, Filipendula glaberrima, Peucedanum japonicum, and Ainsliaea acerifolia) was determined by GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents identified were $\alpha$-phellandrene (18.97%), $\gamma$-terpinene (12.32%), decanal (8.72%), 1-decanol (10.92%), decanoic acid (12.12%), and 2-undecanone (12.32%) from H. cordata, farnesol (2.83%), l-$\alpha$-terpineol (2.72%), benzenmethanol (2.03%), (Z)-3-hexen-1-ol (4.32%), and T-muurolol (2.07%) from F. glaberrima, $\alpha$-phellandrene (14.25%), endobornyl acetate (3.84%), heptanal (47.52%), octanal (2.65%), (E,E)-2,4-decadienal (2.75%), and octanoic acid (4.52%) from P. japonicum, and geyrene (9.74%), $\beta$-cubebene (11.15%), berkheyaradulen (22.32%), $\beta$-elemene (6.21%), (-)-A-selinene (4.85%), benzaldehyde (4.52%), and benzenacetaldehyde (3.40%) from A. acerifolia.

• Journal of the Korean Applied Science and Technology
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• v.20 no.1
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• pp.20-26
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• 2003

Acidic degreasing agent(AADA) was prepared by blending sorbitol, Newpol PE-68, Na-dioctyl sulfosuccinate, Tetronix T-70l, MJU-100A, n-octanoic acid, and phosphoric acid, The physical properties of AADA tested with aluminum specimen showed the following results ; when 3wt% AADA-5 was performed at 70$^{\circ}C$, the degreasing rate was 95% which is comparitively good, and the percentage of etching was 0.277% which was found to be less than that of commercialized product. when 20wt% of AADA-5 was added at 65$^{\circ}C$, the percentage of derusting was 91% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.

• Tribology and Lubricants
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• v.17 no.2
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• pp.109-115
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• 2001

The lubricating performance of 23 kinds of polyol ester base oils 〔POEs〕 having different branch shapes was investigated by using a four ball tribometer under boundary lubrication condition. All the polyol ester base oils used in this study were made up of polyhydric alcohols of two-four valence and normal or branched fatty acids of different carbon number. The wear characteristics of polyol ester base oils are different from those of mineral oil, strongly affected by the branch shapes of fatty acids in their molecles. In particular, the polyol ester base oils having normal fatty acids such as n-octanoic acid, n-nonanoic acid etc. show much better wear performance than POEs having branched fatty acids such as 2-ethylhexanoic acid, 3,5,5-trimethyl hexanoic acid, etc. As the carbon chain length of normal fatty acids, in case of POEs of normal fatty acids, is increased, their wear rate is decreased and, in case of POEs of branched fatty acids, as the degree of branch of branched fatty acids is decreased, their wear rate is decreased. All the wear results of polyol ester base oils could be reasonably explained by comparing cohesive ability among fatty acid molecules in adsorption film by fatty acids obtained as POEs were decomposed.